Slazenger tennis balls have been used on the hallowed turf of the All England Club since 1902.  Tour Core - Tour Core™ is designed to deliver the consistent performance demanded by top players playing in the world's most prestigious tournament. The premium woven material has been specially engineered using the finest wool to create a tighter weave for greater durability and responsiveness.Ultra Vis - The Wimbledon ball utilizes exclusive Ultra Vis dye and a patented application process, creating a ball that has optimal visibility for both players and spectators.Hydro Guard - Using Slazenger's patented Hydroguard™ technology, the fabric is engineered to repel up to 70% more water than a standard ball. This further innovation ensures the Slazenger Wimbledon Ball remains the highest performing tennis ball.ITF Approved - The Slazenger Wimbledon Ball is approved by the International Tennis Federation.